Electric cable.



No. 650,550. Patented May 29, I900.

- M. I. BAIRD.

ELECTRIC CABLE.

Patented May 29, I900. M. I. BAIRD.

ELECTRIC CABLE.

(Application filed Aug, 25, 1899.)

2 Sheets Sheet 2,

(No Model.)

WITN ESSES UNITED STATES PATENT OF ICE MILTON I. BAIRD, or GIiENFIELD, PENNSYLVANIA.

ELECTRIC CABLE.

SPECIFICATION forming part of Letters Patent No. 650,550, dated May 29, 1900.

Application filed August 25,1899. Seria1No.728,405. (it-0mm.)

To all whom, it may concern.-

Be it known that I, MILTON I. BAIRD, a citizen of the United States, residing at Glenfield, in the county of Allegheny and State of Pennsylvania, have invented or discovered certain new and useful Improvements in Electric Cables, of which improvements the following is a specification.

The invention described herein relates to certain improvements in lead-covered electric cables for telephone, telegraph, or other purposes.

The usual custom in ordering cables is for the purchaser to place orders with the manufacturer for the exact lengths wanted. As such lengths are not kept in stock either by the manufacturer or by the supply-houses, they must be made to order, thereby causing great and sometimes expensive delays when the manufacturer is crowded with orders. WVhen orders are received, the manufacturer makes up the cable in one piece, unless of such length as to necessitate making in two or more pieces. The object of making in one piece is to reduce the possibilities of injury to the cable in making splices and consequent absorption of moisture from the air when the cable is opened. Every additional opening further-reduces the efficiency of the cable, especially so on damp days. When such cables are manufactured, the ends are soldered to exclude moisture, and the present practice requires the purchaser,after placing them in position, to open the cables for making any necessary splices and for putting on terminals, and no matter how carefully such work may be done moisture will be absorbed at such opened points, thus reducing the value of the cable.

One object of this invention is .to obviate the necessity of opening or exposing the sealed portion of a cable to the atmosphere, either when making splices or attaching terminals or branch conductors, and also to obviate the necessity of the cable being made to order for the special lengths desired, the cable being manufactured in standard lengths or sections with the conductors exposed at certain points for the connection of other sections or for the connection of terminals or branch conductors. These sections are preferably made of such standard lengths that the multiples of said sections when connected to gether will produce any length desired; and it is a further object of the invention to produce a new article of manufacture which may be kept in stock by the manufacturer or by any supply-dealer and purchased of any desired length and put up at once without waiting to be made to order, thus avoiding delays of manufacture.

A further object of the invention is to provide a simple and ready means of making repairs to grounded, short-circuited, or otherwise injured sections of a cable without opening the cable, which can be done by simply substituting a perfect section for the injured section, the splices being made upon the exposed sections of the conductors and without in any way opening the sealed portion, and also to provide more than one point on each conductor whose attachments can be made with branch conductorswithout opening the cable for that purpose, as is now done.

In the accompanying drawings, forming a part of this specification, Figure 1 is a side elevation of a portion of a cable constructed in accordance with my invention. Fig. 2 is a sectional view of one end of one of the cablesections on an enlarged scale. Fig. 3 is a detail view showing the manner of applying the ceiling-blocks to the cable-wires. Fig. 4 is a transverse section on the line IV IV, Fig. 2. Fig. 5 is a view similar to Fig. 2, showing my invention applied to an anti-induction cable; and Fig. 6 is a view similar to Fig. 2, illustrating a modification in the manner of formingthe ends of the sections. Fig. 7 is an end elevation of a modified form of sealing-block.

As itis now the almost universal practice to form cables of several strands of wire each covered or insulated with paper, which forms the most efficient insulation, I will describe my invention as applied to that class of cables, but do not thereby limit the invention as regards the broad terms of the claims to such cables.

In the practice of my invention the desired number of wires 1, eachinsulated, preferably, by being covered by paper, are bunched to? gether, and the bunched wires then covered with a lead sheath 2 in the usual manner. Such a cable is made or cut into sections, say, of one hundred feet, more or less, in length,

.from the sleeve.

as experience may show desirable. The lead sheath is then'removed for a short distance from each end of the section, exposing the wires, and each Wire is freed from insulation for a short distance. The exposed ends are then spliced to the ends of short pieces 3 of wire covered with a moisture-proof insulation. Suchinsulation may be made of rubber or a fibrous material rendered waterproof in any suitable manner. The splice is then insulated in any suitable manner known in the art. The coupling-wires 3 are passed through holes formed in a block or plug 4 of lead or other suitable material, which is slipped down into close proximity to the splices 5 and then subjected to sufficient pressure to cause the walls of the holes to bear sufficiently tight on the waterproof insulation to form a hermetic seal around each wire. A sleeve 6, of lead or other suitable material, is then placed around the exposed portions of the wires 1 and 3 between the plug and the lead sheath 2, and the ends of such sleeves are hermetically secured, by solder or suitable means, to the sheath and the plug. This sleeve may then be filled, through a hole 7 in its side, with a suitable insulating material, or dry air or a gas may be forced into the sleeve under pressure and the hole closed. The presence of air or gas under pressure inthe sleeve will tend of itself to prevent the entrance of moisture, or the air may be exhausted by heat or otherwise In this manner will be formed a cable-section with both ends hermetically sealed and with the ends of the conductors projecting beyond the seal. Such sections can be made of any desired length and stored without liability of deterioration. If it be desired to make a long length of cable composed of such sections, the wires 3 are made sufficiently long to permit of two blocks or plugs being placed thereon, but separated a short distance, as shown in Fig. The ends a of these wires 3 are then spliced to the exposed ends of the wires 1 of two sections. The exposed portions of the conductors between the plugs and the sheaths of each section are then covered with sleeves, as shown in Fig. 1, the sleeves being soldered or otherwise sealed to the sheaths and plugs. A cable thus formed, consisting of a series of sections connected by exposed eondue-tors,can be most advantageously used for telephone systems. As the sections can be made of a length equal to the distance between poles, the exposed portions afford convenient points to connect the branch Wires leading to houses. If desired, the exposed portions of the conduetors can be connected to binding-posts of terminal boxes on each post, and the branch wires extended from the binding-posts.

In lieu of using the coupling-wires 3 the lead sheath may be removed for a greater distance. The insulation is then removed from the exposed wires or pushed back along the same, and the exposed wi res then covered with rubber, as shown in Fig. (3.

This is preferably done by slipping rubber tubes 8 onto the wires until the inner ends of the tube bear against the insulation on wire 1. The rubber-covered portions of the wires are then'passed through holes in the block or plug at, which is compressed and the sleeve then placed in position, as heretofore stated.

WVhen applying my improvement to anti induction cables, Where the wires are inclosed in pairs or singly in separate passages in the lead cover, the ends of the sections maybe sealed, if the wires have moistureproof insulation, by compressing the lead tightly against the wires at the ends of the section.

Where the ends of the sections can be sealed without employing a plug, as in the anti-induction cable shown in Fig. 5, the sectional cable can be made in long lengths, the conductors being integral throughout the entire length of the cable, as will be readily understood by those skilled in the art.

By employing a plug or block at which is formed with slots extending from the holes or passages through the periphery of the block or plug a sectional cable with integral. or continuous conductors may be formed. In making such a cable the sheath 2 is removed to points a suitable distance apart, dependent upon the lengths of the sections. If the wires are covered with a moistureproof insulation, they are simply separated and passed through the slots into the holes. The plug is then subjected to sufficient pres sure to close the slots and the walls of the holes around the wires. The sleeves 6, which in this case must be split, are then applied to connect the sheaths and plugs. are covered with paper or other material which will absorb moisture, such insulation is removed from the portions exposed by the removal of the sheath and replaced by rubber or other non-absorbent material before the wires are placed in the blocks or plugs.

I claim herein as my invention- 1. A cable consisting of two or more sections, each section provided at each end with a sealing head or block, the conductors being electrically continuous through the entire length of the cable and being exposed or uncovered between the sealing heads of adjacent sections, substantially as set forth.

2. The combination ofalead-covered cable, sealing block or plug provided with holes or passages for the several wires of the cable, the portions of the wires inclosed by the plug being covered with a non-absorbent insulation, and a sleeve connecting the plug and sheath and hermeticallysecured to said parts, substantially as set forth.

In testimony whereof I have hereunto set my hand.

MILTON'I. BATRD.

Witnesses:

DARWIN S. \l otco r r, M. S. MURPHY.

If the wires 

